23760

Appears in sequences

• Orders of non-cyclic simple groups (divided by 4).at n=29A008976
• Numbers k such that phi(k) + sigma(k) = 4*k.at n=0A011254
• Nonprimes k that divide sigma(k) + phi(k).at n=5A011774
• a(n) is the smallest number m such that phi(m) + sigma(m) = n*m.at n=2A015704
• Expansion of (theta_3(z)*theta_3(7z) + theta_2(z)*theta_2(7z))^4.at n=17A028596
• Longest edge a of smallest (measured by the longest edge) primitive Euler bricks (a, b, c, sqrt(a^2 + b^2), sqrt(b^2 + c^2), sqrt(a^2 + c^2) are integers).at n=31A031173
• Longest edge a of smallest (measured by the longest edge) primitive Euler bricks (a, b, c, sqrt(a^2 + b^2), sqrt(b^2 + c^2), sqrt(a^2 + c^2) are integers).at n=30A031173
• Shortest edge c of (measured by the longest edge) primitive Euler bricks (a, b, c, sqrt(a^2 + b^2), sqrt(b^2 + c^2), sqrt(a^2 + c^2) are integers).at n=38A031175
• Least term in period of continued fraction for sqrt(n) is 7.at n=31A031431
• Unitary superperfect numbers: numbers n such that usigma(usigma(n)) = 2*n, where usigma(n) is the sum of unitary divisors of n (A034448).at n=9A038843
• Composite numbers divisible by the palindromic sum of their palindromic prime factors (counted with multiplicity).at n=21A046366
• Expansion of e.g.f. (2 - 4*x + x^2)/((1 - x)*(1 - 2*x)).at n=6A052584
• E.g.f. 1/((1-x)(1-x-x^2)).at n=6A052646
• Number of labeled pure 2-complexes on n nodes (0-simplexes) with 5 2-simplexes and 8 1-simplexes.at n=7A054559
• Smallest number whose set of divisors contains each digit 0-9 at least n times.at n=11A059436
• Ninth column (k=8) of sextinomial array A063260.at n=8A063263
• 9 times octagonal numbers: a(n) = 9*n*(3*n-2).at n=30A064201
• Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,21.at n=32A064247
• Numbers k such that 2k-1 divides 2^k-1.at n=17A081856
• Average (scaled by a certain explicit factor) over all integers k of a_k(n), the n-th coefficient of the k-th cyclotomic polynomial.at n=11A086811